The embodiments herein relate generally to forming proppant-free channels in a proppant packs in subterranean formations using alternating addition of ultra-low density, degradable particulates.
Hydrocarbon producing wells (e.g., oil producing wells, gas producing wells, and the like) are often stimulated by hydraulic fracturing treatments. In traditional hydraulic fracturing treatments, a fracturing fluid is pumped into a portion of a subterranean formation (which may also be referred to herein simply as a “formation”) above a fracture gradient sufficient to break down the formation and create one or more fractures therein. As used herein, the term “fracture gradient” refers to a pressure necessary to create or enhance at least one fracture in a particular subterranean formation location, increasing pressure within a formation may be achieved by placing fluid therein at a high flow rate to increase the pressure on the formation. Then, following the initiation of the fracture, one or more treatment fluids are placed into the formation while the fracture is held open. The term “treatment fluid,” as used herein, refers generally to any fluid that may be used in a subterranean application in conjunction with a desired function and/or for a desired purpose. The term “treatment fluid” does not imply any particular action by the fluid or any particular component thereof. By way of non-limiting example, a “treatment fluid” may be an acidizing fluid, a fracture-initiating fluid, a proppant-laden fluid, etc. Often, a treatment fluid laden with proppant, known as a carrier fluid, is placed into the formation following the fracture fluid. The carrier fluid carries the proppant into the fracture that was formed and then, once the pressure is released, the proppants remain in the fracture where they act to hold apart (“prop”) the walls of the fracture once the pressure is released.
When the fracturing pressure is released, the fracture walls are held apart and not allowed to close by the action of the proppant, and the pressure of the closing helps the proppant hold together as a cohesive proppant bed. Often, proppant is selected to be spherical or substantially spherical, such that the proppant bed retains interconnected interstitial spaces between the proppant particulates that allow flow of fluids through the proppant bed. The greater the volume of space between the proppant grains, either interstitial or otherwise, the greater the conductivity of the resulting proppant pack.